AC compressor replaced, too much oil?

Seems to me you have painted yourself into a corner and then spilled the bucket. That is, you have no idea how much oil is really in the system. There could have been a considerable amount of oil from the old charge remaining.

I say the only real way to "know" is to drain and flush the system and start over.

I haven't kept up with current practice, as we used to be able to use R11 (low pressure) for flushing systems, and that was 'a while' back.

Sounds like you are on the right track, though. Serious "over oiling" will degrade cooling performance.